Buffer mechanism for firearms



DCC. I v C. E' sIMPsv-ON 1,

BUFFER MECHAISM FOR FIREARMS Filed April 8, 1947 I wr Patented Dec. 2l,1948 s PAT-ENT- oFFlcE l* `amended `April"30, 1928i; 370 0.G. 757) Theinvention i describedinrthefollowing speci-` fication and claims: maybe`manufactured' .and

` used by or for the. Government for governmental purposes. withoutithepayment to me ofi any royalty thereon. f i

This invention relates to a buffer mechanism forautomati'creaims,moreparticularly tu firearms having a heavybreech blockwithcorrespondingly large recoil energy.`

The various `buffer `mechanisms of nearlyall` firearms rely largely upon`spring `means tofa'b'` sorb the recoillenergy of thesreciprocatingbreechmember. Whilesuch mechanismswiov absorb the recoil lenergy fairlysatisfactorily; such mechanisms havethe disadvantage `ofimpartingfa re`gradually Vabsorb the recoil energy when the Although 'the breech blockstrikes Isuch 'buiten material contained in thestack of disks-doeshaversome resiliency, it is relatively slight so that the effect of thebreechlblocl striking such a' buier is about the same asif strikinga'solidobject. `Hence a severeshock` is `appliedto therearm when therearward travelof thebreechbloc'k is suddenly arrested. There isafurther disad-V vantage Vin vthat the breech block member reboundsafter impact with suchabuffer which affectsthe timing and feeding, ofthenrearm.

Accordingly, it is an object `of lthis. invention pto provide a buffermechanism for a firearm` wherein the recoil energy of the `reciprocating`breech member of the firearmis gradually absorbedrsc as. tosubstantially eliminate `any rebound of the breech'block fromthe buffer`mechanism.

A particularobject of this *invention isfto pro# vide a` buier mechanismfor `a firearm such as disclosed'in my copendingapplication for Fire?arm, Serial No. 675,124, led June 1, 1946.

Thespecic nature of the .inventionas wellies'- other `objects and.advantages thereofA willtclearly appear 'Ironia descriptionof :ra:preferred embodi` ment. as 'shown in the accompanying `.drawings inwhich: l

Fig. 1 is. 'an enlargedgpartiallside.elevational view of a. rearm shownin longitudinal Vsection illustrating the elements ofthe buffermechanism of this invention;

Fig. 2 isa perspectiveview of the buffer sleeve; Fig. 3. is a top viewof the buffer mechanism housing, shown-positioned in the rear of a rearmreceiver;

Fig. 4l is `an enlarged detail side elevational view of theoutertelescoping tube having a coni-l cally shaped end; and

Fig. 5. is 1a side elevational view of the inner telescopng tube.

i This .invention essentially comprises a housing adapted to slidablycontaintwo telescoping tubes.- The innermost of such tubes contains aAspring. Conical shoulders are provided on each of the telescoping tubeswhich abut a sleeve having cor respondingly shaped sides. The recoilenergy ofv the reciprocating member of the rearm is absorbed by thebuffer mechanism when such memberv strikes the 'tube projectingforwardly from the housing. Such force telescopes the two tubesbyexpanding the buler sleeve placed between the two conical shoulderslof the telescoping tubes` thereby dissipating the recoil energy againstthe bore of thefhousing. The spring contained within the `innertelescoping tube acts to return theE mechanism forwardly to its'normallocationwhen the breech block starts toward battery position.

There is shown in Fig. 1` a portion of a firearm including `the buffermechanism which embodies this invention. y The elements of the buffermech anism are `contained within a housing Ill secured to the rear endof a firearm receiver II. Hous. ing I0 comprises a substantiallyrectangular block portion I`4 which has formed thereon an integralrearwardly projecting, cylindrical boss I2. The rectangular portion I4of housing I0 serves as a' rearspacer for receiver II to which aresecured the side plates of such receiver. An axial bore I3is provided inboss I2 which passes through the block portion YIII of housing IIJ, suchbore being of reduced diameter as shown at I5 when it emerges from theforward face of block I4. Boss `I 2 is pro-l vided with threads I6 ontheouter periphery thereofto receive a buffer cap Il, such `buffer cap 2|of tubes I8 and I9 respectively. The closed end 2Ifof tube I9 is ofreduced diameter so as to project forwardly through reduced diameter portion lo of bore I 3,"such reduced diameter portion oftube I9 forming ashoulder 22 which limits the Each of such tubes A amount of protrusionof tube I9 from housing I'IJ. The open end of tube I9 is conicallyshaped as shown at 23 for a purpose to appear presently.

Tube I9 is slidably contained within bore I3 of housing I0. Tube I8 isslidably Ucontained within tube( I9 and the open endof such tubel has anenlarged conically shaped head portion 24. When tube I8 is positionedwithin tube I9 .Y

is disposed the conically shaped head portion 24 rearwardly withinhousing I0. y

A buffer sleeve 25 is placed about tubeul 8,. Such n ishere provided abuffer mechanism capable of i receiving and dissipating the recoilenergy of a buffer sleeve has inwardly taperedends 26 having a tapercorresponding to that of conical head 24 of tube I8 and conically shapedend 23 of tube I9. Thus when sleeve 25 surrounds tube I8 the inwardlysloped end 26 of such sleeve cooperates with conical head portion 24 oftube I8, while the opposite similarly tapered end 26 of sleeve 25cooperates with conical end 23"of `tube I`9, to provide a wedging orcamming action as will be later described.

The sleeve 25 is preferably made from a material having a lowcoefficient of friction such as a bronze alloy and such sleeve ispreferably split to permit greater expansion thereof.

A buffer spring 28 is inserted within tube I8, one end being in abuttingrelationship with the closed end of such tube, while the other end ofspring 28 abuts the inside face of cap I'I to retain such spring withintube I8. Spring 28 is centrally positioned again-st cap I'I by a stud 29axially secured on the inside face of such cap. Spring 28 acting againstthe closed end of tube I8 forces the entire buffer mechanism forwardlyso that shoulder 22 of tube I9 `abuts a corresponding shoulder 3!provided on the inside of housing Ill formed by the reduced diameterportion I5 of bore I3. f

A breech block 39 i-s slidably contained within receiver II and suchbreech block is returned to battery position by the operating or drivingsprings (not shown). When aA cartridge is discharged in the firearm,breech block 30 vis driven rearwardly with considerable force andk suchenergy as is not absorbed by other recoil checking means is absorbed bythe buffer mechanism contained within housing I0. When the rear end ofbreech block 38 strikes the forwardly disposed closed end 2| of tube I9,such tube is driven'rearwardly. The conical end 23 Aof tube I'9 being inengagement with the inwardly sloped end 26 of sleeve forces such sleeveand tube I8 rearwardly at the same time expanding sleeve 25 kand thencompressing spring 28. However as the buffer mechanism is forcedrearwardly, the component of the rearward force is directed Alargely tothe bore of housing I9. Spring 28 biasing tube I8 forwardly resists therearward movement of sleeve 25 thereby assisting the expansion of sleeve25. Therefore the rearward force of breech block 39 is dissipated infriction against the Walls of housing I0. The expansion of sleeve 25increases the frictional force against the bore of housing I0 in itsrearward movement thereby completely absorbing the recoil energy ofbreech block in the short distance of travel permitted by the buffermechanism. When the recoil force of breech block 38 is completelyabsorbed, the telescoping tubes I8 and I9 are in a collapsed or fullytelescoped position and remain so until the operating `spring (not,shown) starts return of the breech blockto batlf tery position whereuponthe tubes separate by'- action of spring 28.' Such sprlngfo'rces tubes.`

reciprocating breech block without causing any objectionable rebound ofthe breech member. The vbuffer sleeve 25 is expanded against the bore ofthe buffer housing by tubes I8 and I9 and the whole buffer mechanismtravels rearwardly. The expanded buffer sleeve holds the buffer springunder compression until such time as the breech 'member goes forwardlywhereupon the buffer A spring returns the buffer mechanism forwardly.

"One of the unique features of this invention as previously pointed out,resides in the buffer mechanism being returned forwardly in a relativelygradual manner instead of being shot forwardly as is commonwith mostbuffer mechanisms. `The engagement of buffer sleeve 25 with the bore ofhousing IIJ is responsible for such slow return.

In practice the buffer mechanism herein de-i scribed has,` reduced theforward velocity of the reciprocating breech member by as much asonehalf that of conventional buffer mechanisms. Thus it is plainlyobvious that improved timing and feeding can be achieved when utilizingthe buffer mechanism of this invention. It is further pointed out thatthe buffer mechanism herein'described is of simple and ruggedconstruction lending itself to ease and rapidity 4of fabrication.-

insaid housing and arranged for limited longi-l tudinal movement,l asplit sleeve surrounding one of said tubes, said tube constructed toretain said sleeve thereon, said other tube abutting said sleeve, andresilientmeans maintaining one of' said tubes in the path of thevbreechmember to receive the impact thereof, said sleeve beingconstructed and arranged to transmit the force of impact of the breechmember to said housing.

2. In al firearm having a reciprocating breech member, a buffermechanism comprising, a hous-v ingsecured to the firearm, said housinghaving a longitudinal bore therethrough, a stepped shoulder in saidbore, a first tube having a closed end slidably mounted in said bore,said first tube constructed and arranged to abut said shoulder whilesaid closed end projects forwardly out of saidl housing, a second tubehaving a closed end, said second tube being inserted in said rst tubewith said closed end adjacent saidvclosed end of said first tube, asplit sleeve surrounding said second tube and abutting the open end ofsaid first tube, said second tube being' constructed to retain saidsleeve thereon, and resilient -means for maintain` ing' said rst tubein'the path of the breech memf ber to -receive -theimpact thereof, saidsleeve bejj ing constructed and arranged to transmit' 'the' force ofinmactv of the breech member to the bore of said 'housingx-x."

3. In a firearm having a reciprocating breech member, a buffer mechanismcomprising, a housing having a longitudinal bore therethrough, a steppedshoulder in said bore, a first tube having a closed end slidably mountedin said bore, said rst tube constructed and arranged to abut saidshoulder While said closed end projects forwardly out of said housing,said first tube having a coni cally chamfered open end, a second tubehaving a closed end, said second tube having an annular conical ringdisposed about the open end thereof, said second tube being slidablymounted within said first tube with said closed end adjacent said closedend of said first tube, a split sleeve surrounding said second tube,said sleeve having an inwardly tapered edge on each end being engaged onone end by said conical end of said rst tube and by said ring of saidsecond tube on the other end thereof, and, resilient means formaintaining said rst tube in the path of the breech member to receivethe impact thereof whereby said sleeve by expansion transmits the forceof impact of the breech member to the bore of said housing.

4. In a firearm having a reciprocating breech member, a buier mechanismcomprising, a housing having a longitudinal bore therethrough, a

said first tube constructed and arranged to abut said shoulder Whilesaid closed end projects forwardly out of said housing, said first tubehaving a conically chamfered open end, a second tube having a closedend, said second tube having an annular conical ring disposed about theopen end thereof, said second tube being slidably mounted Within saidrst tube with said closed end adjacent said closed end of said firsttube, a split sleeve surrounding said second tube, said sleeve having aninwardly tapered edge on each end being engaged on one end by saidconical end of said first tube and by said ring of said second tube onthe other end thereof, and a helical spring in said second tube arrangedto bias both of said tubes and said sleeve Vforwardly in position toreceive the impact of the breech member to permit expansion of saidsleeve thereby transmitting the force of such impact to the bore of saidhousing.

5. In a firearm having a reciprocating breech member, a buier mechanismcomprising, a housing having a longitudinal bore therethrough, a steppedshoulder in said bore, a rst tube having a closed end slidably mountedin said bore, said first tube constructed and arranged to abut saidshoulder while said closed end projects forwardly out of said housing,said rst tube having a coni cally charnfered open end, a second tubehaving a closed end, said second tube having an annular conical ringdisposed about the open end thereof, said second tube being slidablymounted within said first tube with said closed end adjacent said closedend of said first tube, a split sleeve surrounding said second tube,said sleeve having an inwardly tapered edge on each end being engaged onone end by said conical end of said first tube and by said ring of saidsecond tube on the other end thereof, a helical spring inserted in saidsecond tube, a cap member secured to said housing to retain said springin said second tube, said spring being provided to resist rearwardmove'- ment of said sleeve on impact of the breech member With saidclosed end of said first tube to permit expansion of said sleeve totransmit the recoil energy of the breech member to the bore of saidhousing and t-o return said tubes and sleeve forwardly as the breechmember returns to battery position.

CLARENCE E. SIMPSON.

REFERENCES CITED The following references are of record in the nie ofthis patent:

UNITED STATES PATENTS Number Name Date 1,351,141 Thompson Aug. 31, 19202,335,854 Green Dec. F7, 1943 2,420,701 Dath May 20, 1947 2,426,661Anderson Sept. 2, 1947 2,431,376 Dath Nov. 25, 1947

